Olive oil containing food composition

ABSTRACT

A method has been found for the manufacture of a spread which is characterized by the presence of a substantial amount of olive oil polyphenols and the absence of olive oil odor. The deodorized olive oil to be used for the preparation is obtained by a mild refining process which spares the olive oil&#39;s minor components.

[0001] The present invention deals with a fat containing foodcomposition, particularly a spread, which contains a substantial amountof olive oil. Such composition is believed to fit in a healthy dietparticularly by helping to control blood cholesterol content. Theinvention also comprises a process for preparation of the composition.

BACKGROUND OF THE INVENTION

[0002] The present invention deals with a food composition with asubstantial fat content. Since fat consumption is associated with anincreased risk of cardiovascular disorders, the nutritional value ofdifferent types of fat as well as methods for reducing the fat contentof fat compositions had been the object of extensive investigations.Presently not only the triglyceride part of fats is the subject ofinvestigations, but also the nature and the effects on health of fatattributes, the so-called minor components which are present in smallamounts in non-refined natural fats. It has recently been found that theminor components which are denoted as anti-oxidants, including fatpolyphenols, positively interfere with the body's cardiovascular system.

[0003] Traditionally, natural fats are refined before they are used asan ingredient for the preparation of food. However, traditional fatrefining is not discriminating to the nature of the fat ingredients andaims at the removal of all substances other than triglycerides,including minor components.

[0004] Spreads are food compositions which usually contain a substantialamount of fat, often 40 wt. % or more. Usually the fat consists of aliquid oil and a structuring fat which gives the fat blend a properconsistency. Olive oil is a valuable nutritional fat because of its highcontent of oleic acid. Olive oil has been incorporated in foodcompositions either unrefined or fully refined. In EP 421 504 spreadsare described in which the fat phase consists partially of unrefinedolive oil. According to GB 2281304 refined olive oil is used in theliquid oil blend of the fat phase for spread manufacture. Even when usedin small amounts, the incorporation of unrefined olive oil imparts amuch pronounced flavour and taste. The characteristic olive oil flavouroften is appreciated, but by many people this flavour occurring inspreads is perceived as offensive and therefore is unsuitable forspreads. Hence the olive oil has to be deodorised by a refiningtreatment. Olive oil traditionally is deodorized at temperatures of 250°C. or even more. Under such drastic conditions also the oil's minorcomponents, including natural anti-oxidants, particularly the typicalolive oil polyphenols such as oleuropein, its aglycon (shortly aglycon),tyrosol and hydroxytyrosol, are nearly fully stripped away.

[0005] WO 97/06697 teaches that food products can be fortified withanti-oxidants, including polyphenols and particularly the water solubletea polyphenols.

[0006] Polyphenols present in olive oil are more or less fat soluble andhave a chemical composition which is different from the water solublepolyphenols. They are presumed to play in the body an anti-oxidant rolein specific tissues, possibly because of their fat solubility.

[0007] When incorporating a substantial amount of olive oil polyphenolsin spreads, imparting a strong olive oil odour could not be avoided upto now.

SUMMARY OF THE INVENTION

[0008] We have found an olive oil containing spread which contains aconsiderable amount of olive oil polyphenols but which nevertheless isfree from any offensive olive oil odour. The invention makes use of aprocess for mild olive oil refining which allows largely retaining thepolyphenols. With this process the prejudice has been overcome thatproper olive oil refining requires drastic refining conditions withregard to temperature and process time. Traditional refining removesfree fatty acids, resulting in a content of less than 0.1 wt. %. Thefound refining conditions relating to flow of sparging gas, temperature,pressure and process time are less drastic, but nevertheless areappropriate for the removal of olive oil odour and—to a large extent—offatty acids, so that the refined olive oil is pure enough to be used forthe manufacture of a spread, while the process spares a major part ofthe minor components, including the olive oil polyphenols, tocopherols,squalene and further unsaponifiables, including fatty alcohols andsterols, many of which are believed to be valuable nutrients. Theprocess should be mild enough that at least 1500 ppm of squalene areretained in the olive oil.

[0009] The obtained olive oil can be used for the manufacture of spreadcompositions in which olive oil but not its odour is a desiredingredient. The invention therefore consists in an oil containing spreadcomposition where 5-100 wt. % of the oil consists of olive oil and whichhas no perceivable olive oil odour, characterised in that thecomposition contains at least 10 ppm of olive oil originatingpolyphenols.

DETAILS OF THE INVENTION

[0010] The olive oil containing spreads of the present invention areprepared according to common spread manufacturing process technology.Examples of spread processing can be found e.g. in GB 2281304 and in EP421 504. Generally spreads are emulsions of a water phase and a fatphase, while the fat phase ususally consists of both liquid oil and astructuring fat. According to the present invention 5-100 wt. %,preferably 5-95 wt. %, more preferably 10-95 wt. %, still morepreferably 20-95 wt. % of the liquid oil of the fat phase of theemulsion consists of olive oil which has been subjected to the mildrefining process of the present invention.

[0011] The invention also comprises a process for the manufacture of anyfood composition which contains 0.1-90 wt. % of olive oil, which processcomprises selecting the usual ingredients, including an olive oilsource, and employing the usual processing steps, characterised in that10-100 wt % of the selected olive oil has been obtained according to theprocess of the invention. The obtained composition may exhibit an oliveoil flavour when besides the mild refined olive oil obtained accordingto the present invention also some ingredient having an olive oilflavour is added as well. So the benefits of a relatively cheap sourceof refined olive oil and high levels of polyphenol and flavour arecombined. The olive oil flavour source might be e.g. a precious virginolive oil or a proper substitute, e.g. those obtained by the methodsdescribed in WO 97/03566 and EP 852 116.

[0012] In order to retain after refining a sufficient amount ofpolyphenols a level of 100 ppm of polyphenols in the starting olive oilis preferred. The starting olive oil preferably is a cheap Lampante oilwhich usually contains substantial amounts of free fatty acids.Generally, Lampante oil contains from 20 ppm up to 250 ppm ofpolyphenols.

[0013] The refining process not only removes the olive oil odour butalso the excess of free fatty acids. High amounts of free fatty acids,even 7 wt. % or more, are often found in Lampante grade olive oils. Themild refining process reduces the fatty acids content to less than 2 wt.%, even down to 0.3 wt. %, which is quite acceptable. Under the mildconditions of the present process the free fatty acids content can beeasily reduced to less than 2 wt. %, but obviously the usual low levelof 0.1 wt. % is not attained, unless the starting olive oil is alreadylow in free fatty acids.

[0014] Polyphenols are compounds which share a phenolic hydroxyl group.Olive oil originating polyphenols are known to comprise oleuropein,aglycon, tyrosol, hydroxytyrosol and caffeic acid. Their source is oliveoil and the olive fruits from which the olive oil is pressed. The totalcontent of polyphenols in olive oils can be established by standardmethods e.g. by the widely accepted calorimetric Gutfinger method asdescribed in J.Am.Oil.Chem.Soc. 1981, 11, pp. 966-968, which method isbased on the reaction of a methanolic extract of olive oil and theFolin-Ciocalteau reagent. This method has been used for establishing thepolyphenol values mentioned in the present patent specification.

[0015] The olive oil is sparged with an inert gas at a temperature up to250° C. under such conditions of sparging gas flow, pressure and processtime that the refined oil is free from olive oil odour and stillcontains at least 1500 ppm of squalene. Suitable refining conditions arechosen from ranges of relatively moderate sparging temperatures andpressures, particularly 120-250° C. and 2-5 mbar, respectively, usingpreferably 1-15 m³ steam per kg of oil. At 250° C. one hour sparging hasappeared to be a suitable process time, but time is prolonged to 5 hourswhen refining takes place at 120° C. Suitable conditions can beestablished easily by some trials.

[0016] Squalene is a high molecular weight ingredient, which occurs at alevel of 1500-7000 ppm in crude olive oil, including unrefined Lampanteoil. Olive oil when refined at traditionally high temperatures containsonly little squalene, less than 1500 ppm. An olive oil which has beenobtained according to the mild refining process of the present inventionhas retained squalene at a level of at least 1500 ppm. Experiments haveshown that such concentrations can go along with a proper deodorisation.Therefore the content of native squalene has appeared to be a suitablemarker for the refining depth of olive oil. A low squalene contentpoints to a great depth of refining carried out under relatively drasticconditions. Such conditions are avoided with the process according tothe present invention.

[0017] The polyphenols of olive oil are more volatile than squalene, butwith the present conditions are retained for a major part in the refinedoil. Besides squalene also the above-mentioned unsaponifiables (at least4500 ppm unsaponifiables) are retained in the mild refined olive oil.The polyphenol containing spreads prepared according to the inventioncan be distinguished from known odour-free olive oil containing spreadsin that they contain squalene in a concentration which is proportionalto the concentration of squalene in the used mild refined olive oil. Theinvention comprises spreads which contain at least 5 wt. % of olive oil,but which are free from olive oil odour and contain at least 75 ppm ofsqualene.

[0018] Olive oils obtained according to the invention may contain e.g.90 ppm of polyphenols when refined at 210° C., while the amount drops to30 ppm when refined at 245° C. Process time and pressure being the samein both cases: about 1.2 hours and about 2.5 mbar. Generally spoken,when a free fatty acid content up to 1 wt. % is allowed, at least 60 wt.% of the polyphenols is retained after refining of the olive oil.

[0019] Hence, the olive oil resulting from the found process contains atleast 1500 ppm of squalene and is characterized further by the absenceof olive oil odour on the one side and by a relatively large amount ofnative polyphenols on the other side. In practice, absence of olive oilodour is decided when a sensory panel perceives no flavour differencebetween a composition prepared with an olive oil which has been mildrefined according to the invention and a composition prepared with thesame ingredients, employing the same processing, but containing an oliveoil which has been fully refined in the traditional way.

[0020] Spreads obtained according to the invention can be recognizedbecause they are characterized by a specific partition of the varioustypes of olive oil polyphenols, which partition is caused by the mildrefining conditions which have a different effect on the individualpolyphenols. The partition therefore is a kind of fingerprint whichreflects the applied refining conditions.

[0021] For proper stabilisation of the spreads measures have to be takenin order to prevent flavour reversion. Flavour reversion is known tooccur easily when no proper attention is paid to the removal of metalions from the olive oil, particularly of iron and copper ions which arenotorious catalysts for oil degradation. According to a preferredembodiment the refining treatment therefore includes measures which aimto reduce the concentration of said metal ions to less than 0.1 ppm.Well known procedures include e.g. the treatment of the olive oil withphosphoric acid and/or with a suitable absorbing bleaching earth,particularly under so-called wet bleaching conditions where the oil hasto contain a small amount (0.2 wt. %) of water.

[0022] As said before the present mild refining treatment removes thefree fatty acids only partially. Under traditional olive oil refiningstandards the remaining content, amounting to 0.3-2 wt. %, is notconsidered good enough. Fatty acids in such small amounts do not affect,however, product safety or oil taste, while product stability is hardlyaffected, provided metal ions have been removed.

[0023] It has appeared that the taste and stability of spreads preparedwith the mild refined olive oil complies with the standards set forspreads prepared with traditionally refined olive oil.

[0024] The invention is illustrated by the following examples:

EXAMPLE 1 Olive Oil Refining

[0025] Crude olive-oil (30 ton), which contained 3.2 wt. % of free fattyacids, 110 ppm of polyphenols and 3000 ppm of squalene was heated up to90° C. and washed by thoroughly mixing with 7 wt. % of soft water of 90°C. The water phase was separated from the olive oil in a self-cleaningcentrifuge. By vacuum drying at 50 mbar the olive oil became dry.

[0026] The washed and dried olive oil maintained at a temperature of 90°C. was first vigorously stirred after addition of an aqueous 50 wt. %phosphoric acid solution (0.8 l per ton of oil). After separation of theaqueous phase by centrifuging, demineralized water was added (0.6 l perton of oil), followed by the addition of bleaching earth (VOLCANSILDE22™, 4.5 kg per ton of oil). After 20 min of stirring the pressure waslowered to 40 mbar and stirring was continued for another 20 min. Thenthe bleaching earth was removed by filtration.

[0027] The bleached olive oil was degassed at 100° C. and 30 mbar andthen gradually heated up to 238° C. over one hour. After subsequentsteam sparging at 2.3 mbar, spending 9 kg of steam per ton oil, the oilwas cooled down to 25° C. over one hour and finally cleared byfiltration. Analysis showed that the refined olive oil contained 0.3 wt.% of free fatty acids, 65 ppm of polyphenols and 3000 ppm of squalene. Asensory panel assessed the olive oil flavour. Using a scale with tastescores ranging from 4 (rejected) to 8 (excellent) the panel assigned tothe oil a rating of 7, which is almost excellent, while olive oilflavour was hardly perceivable. Even after 4 months of storage no tastedefects were noticed. An average olive oil after been deodorized for onehour at the normal temperature of 255° C. contains: 0.1 wt. % of freefatty acids, 1400 ppm of squalene and less than 10 ppm of polyphenols.

EXAMPLES 2-5 Olive Oil Refining

[0028] Example 1 was repeated, except that the sparging temperatureswere varied as indicated in Table I while exposure times were about thesame, but slightly different which explains the variations forpolyphenol content. TABLE I Sparging Polyphenols Free fatty acid Ex.temperature ° C. content ppm content wt.% 2 210 88 1.34 3 220 63 0.89 4230 81 0.52 5 234 62 0.41

EXAMPLE 6 Spread Containing Mild Refined Olive Oil

[0029] A spread was prepared using a water phase and a fat phase havingthe composition as shown in Table II. The fat phase and the water phasewere emulsified by vigorous stirring and pasteurized at 60° C. With aflow of 5-6 kg/h the pasteurized emulsion was conducted through TABLE IIwt. % FAT PHASE 60 fat blend¹ 59.55 Hymono 8903 ™ 0.08 Bolec ZTD ™ 0.08beta-carotene² 0.2 flavour 0.09 WATER PHASE 40 skimmed milk powder 1.2salt K-sorbate 0.1 lactic acid until pH = 5 tap water balance up to 40

[0030] a Lab Votator™ line A-A-C. Processing conditions for A1: 800 rpm,exit 20-22° C., A2: 800 rpm, exit 6° C. and C (50 ml): 250 rpm.

[0031] The obtained spread was judged on aspects including flavour,colour, taste, taste stability, spreadability, consistence and stabilityof consistence. The spread exhibited excellent quality in all aspects. Acomparison spread was prepared under identical conditions and with thesame ingredients, except that an olive oil was chosen, qualified as pureolive oil, which was obtained by traditional refining at a relativelyhigh temperature. However, a sensory panel could perceive a tastedifference between both spreads, neither immediately after preparation,nor after 5 weeks of storage.

1. An oil containing spread composition, where 5-100 wt. % of the oilconsists of olive oil, which has no perceivable olive oil odour, andwhich composition contains at least 10 ppm, preferably at least 50 ppm,more preferably at least 200 ppm of olive oil originating polyphenols.2. A spread composition according to claim 1 which composition containsat least 50 ppm of olive oil originating polyphenols.
 3. A spreadcomposition according to claim 1 which composition contains at least 200ppm of olive oil originating polyphenols.
 4. A spread compositionaccording to claim 1 which contains at least 5 wt. % of olive oil and atleast 75 ppm of squalene.
 5. A process for refining an olive oil whichprocess comprises sparging the oil with an inert gas at a temperature upto 250° C. under such conditions of sparging gas flow, pressure andprocess time that the refined oil is free from olive oil odour andcontains at least 1500 ppm of squalene.
 6. A process according to claim5 where the olive oil to be refined, the source oil, contains at least100 ppm of polyphenols.
 7. A process according to claim 5, where therefining conditions are such that at least 60 wt. % of the polyphenolspresent in the source oil are retained.
 8. A process according to claim5 where the sparging temperature is 120-250° C.
 9. A process accordingto claim 5 where the sparging pressure is 2-5 mbar.
 10. A process forthe manufacture of a food composition which contains 0.1-90 wt. % ofolive oil, comprising the steps of
 1. selecting the ingredients usualfor the composition, including an olive oil source, and
 2. employing theprocessing steps usual for obtaining the composition, where 10-100 wt %of the selected olive oil has been obtained according to claim 5.